This invention relates generally to systems for recording and/or reproducing color video signals. More particularly, the invention relates to a color video signal recording and/or reproducing system wherein tracks are formed on a magnetic recording medium, in mutually close proximity and without guard bands therebetween. The recorded color video signals are reproduced in a manner which prevents generation of crosstalk between the closely disposed magnetic tracks.
Among video signal recording and/or reproducing systems known heretofore, there is one wherein video signals are successively recorded on a magnetic tape in a plurality of tracks which are inclined or oblique relative to the longitudinal direction of the tape. In general, beat disturbances will occur in a system of this type when the picture is reproduced, if the video head reproducing the picture does not scan the correct track. The head becomes offset from the originally recorded track (i.e. the head follows a displaced track or tracking deviation). Then it reproduces two adjacent tracks at the same time. Accordingly, in order to prevent this beat disturbances from occurring, heretofore the video signal have been recorded along tracks formed with unrecorded portions between them, or so-called "guard bands". These guard bands prevent the video head which is scanning one track from also simultaneously scanning an adjacent track, although the video head may undergo some tracking deviation.
However, in a system for recording video signals on tracks with guard bands left between the tracks in this manner, the portions of the magnetic medium forming the guard bands cannot be used for recording and reproducing of signals. For this reason, there is a poor efficiency in the utilization of the tape.
Accordingly, a proposed recording system tracks which are formed in close proximity to each other, sometimes records on without a leaving guard bands therebetween. This proposed system is supposed to improve the tape utilization efficiency. By this proposed system, the inclinations or azimuths of the respective gaps in two video recording heads are set so that they are inclined in mutually opposite directions with respect to the vertical direction. Consequently, mutually adjacent tracks on the tape are always scanned by video heads for reading different azimuth angles. For this reason, when one of the video heads is scanning a specific track, an adjacent track is also being reproduced. However, the azimuth loss is great and the reproduction level is low with respect to the signal of this adjacent track, whereby crosstalk can be reduced. However, in this recording and/or reproducing system, the effect of azimuth loss is smaller at the lower frequencies of the recorded signal. Consequently, crosstalk becomes great at these low frequencies. Particularly, there is crosstalk when the above described recording and/or reproducing system is applied to a system wherein a color video signal is separated into a carrier chrominance signal and a luminance signal. A frequency modulated luminance signal is obtained by frequency modulating a carrier wave with this luminance signal. A carrier chrominance signal is frequency converted to a band lower than that of this frequency modulated luminance signal, and then is mixed and multiplexed with it. The resulting multiplexed signal being recorded on a tape. Much crosstalk occurs with respect to the carrier chrominance signal which has been frequency converted to a low-frequency band. Consequently, a color picture of good quality cannot be obtained by this system. Accordingly, with the aim of solving this problem, a system has been proposed in which the gaps of two video heads have different azimuth angles. In addition, during recording the chrominance signal is removed during each horizontal scanning period (1H) in the recording signal.
However, in this system, there is a color burst signal only during every other 1H, in the processing of the reproduced chrominance signal in the reproducing system. For this reason, color stability cannot be attained with high precision with respect to time axis fluctuations.